Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3291—Characterised by the shape of the carrier, the coating or the obtained coated product
  • B01J20/3293—Coatings on a core, the core being particle or fiber shaped, e.g. encapsulated particles, coated fibers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
  • B01J13/16—Interfacial polymerisation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J45/00—Ion-exchange in which a complex or a chelate is formed; Use of material as complex or chelate forming ion-exchangers; Treatment of material for improving the complex or chelate forming ion-exchange properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
  • B01J2220/52—Sorbents specially adapted for preparative chromatography

Definitions

• the present invention relates to capsules with a composite structure consisting of a polymer membrane and a core comprising a complexing polymer, their preparation process and their various applications as complexing, decomplexing and separation agents.
• silica or resins can be used for the separation of a limited diversity of compounds and are poorly suited for the separation, for example, of cations or metal anions.
• certain techniques have been developed; however, for various reasons, they are not entirely satisfactory.
• complexing ligands the best known representatives of which are crown ethers, to name but a few.
• crown ethers are today mainly used as such for their intrinsic properties in liquid-liquid extraction systems.
• One of the drawbacks of this method is that it is not easy to handle and recover the crown ethers when they are in their liquid form.
• Liquid elution chromatography is also known using, as stationary phase, resins obtained by grafting a crown ether on an organic support (polystyrene beads: cf. G. Zirnhelt et al., Sep. Sci. Technol., 28 (1993), 2419-2429; or crosslinked polyacrylate) or mineral (particles of macro- or micro-porous silica: cf. M. Lauth, thesis of the Louis Pasteur University, France, September 14, 1984) .
• crown ethers and other similar ligands, have quite interesting complexing properties, allowing, if they were easier to handle and especially in more concentrated form, their use in fields as varied as the decontamination of air or soil, up to human medicine, such as decontamination of the blood, the thyroid or even as components of medical imaging products, this list however not being limiting or exhaustive.
• the techniques for retaining active substances are, for example, methods which consist in preparing individualized particles made of a material coating said substance. These particles have sizes between a few nanometers and a few millimeters. Among these are reservoir particles made up of a continuous solid membrane which envelops a heart filled with active material. These reservoir particles are called capsules.
• encapsulated product indicates that a product is enclosed, in the solid or liquid or even gaseous state, alone or in combination with formulating agents, in a hollow body, the capsule, in order to isolate it. from the outside environment.
• the capsule therefore generally consists of a membrane whose role is, on the one hand to isolate the active substance from the external environment, and on the other hand to allow better conservation of said active substance, or even a vectorization and / or immediate, prolonged, delayed and / or controlled release of this active substance encapsulated in the conventional uses which are made of encapsulated products.
• Another technique uses the technique of interfacial polycondensation in a dispersed medium, technique disclosed, for example by PW Morgan et al., J. Polym. Sci., 40, (1959), 299-327, for the synthesis of flat films.
• This technique has been adapted to the synthesis of capsules (R. Arshady, J. Microencap., 6 (1), (1989), 1-10 and 13-28).
• the latter technique leads to capsules having a mechanical strength suitable and sufficient for many applications, and in particular for the production of chromatography columns.
• the membrane of these capsules is made of a porous polymer, thus easily allowing the exchange of materials between the external environment and the heart of the capsule.
• a first objective of the present invention to obviate all of the drawbacks associated with the various techniques proposed in the prior art described above.
• one of the objectives of the present invention is to provide materials with high complexing power and easy to handle.
• Yet another objective is to provide complexing materials, easily manipulated, with high complexing power, and whose structure remains substantially unchanged and does not vary or slightly when used, in particular during many complexation / decomplexation cycles. .
• the present invention also aims to provide complexing materials with a broad spectrum, that is to say having a strong complexing power for a large number of chemical species, such as for example cations or metal anions , alkali and alkaline earth, as well as their isotopes.
• Another objective also consists in proposing complexing materials which are mechanically stable and intended for the selective separation of metal ions.
• Another object of the present invention to provide complexing materials in a form weakly or even non-toxic to humans and the environment.
• the present invention firstly relates to complexing composite capsules, characterized in that they essentially consist of: a) a core comprising agents capable of complexing and / or decomplexing chemical entities, said agents being functionalized with one or more monomers having undergone polymerization; and b) a polymer membrane formed by polycondensation of at least two monomers, said membrane enclosing said core and being permeable to said chemical entities.
• the composite capsules according to the invention are advantageously obtained by interfacial polycondensation in a dispersed medium (PCI).
• PCI dispersed medium
• This type of preparation makes it possible to obtain capsules having the mechanical strength required for the applications envisaged in the context of the present invention.
• the membranes of the capsules obtained according to this process also offer an optimal degree of porosity for the said applications.
• this polycondensation process at the interface of two liquids generally consists in creating a dispersion of one liquid in another.
• the two liquids must be substantially immiscible with one another, such as for example a lipophobic phase and a lipophilic phase, generally an aqueous phase and an organic phase respectively, thus forming a continuous phase (or dispersing phase) and a dispersed phase.
• a solution comprising a monomer Mi, as well as the complexing active substance proper, dissolved in a solvent Si is dispersed in a solution comprising a solvent S 2 not containing reactive species.
• the monomer M 2 soluble in S 2 , of the dispersing phase is added.
• the condensation reaction between Mi and M 2 possibly catalyzed, takes place at the interface of the dispersing phase and the dispersed phase. We then speak of interfacial polycondensation.
• the principle of interfacial polycondensation consists in carrying out a dispersion of one solution in another, the two solutions being immiscible with one another.
• Si is a solvent for Mi, but is not substantially miscible in S 2 which is a solvent for M 2 . If Si is the solvent for the lipophobic phase, there will be a dispersion of Si in S 2 , that is to say of the water-in-oil type (reverse system). Conversely, if Si is the solvent for the lipophilic phase, there will be an oil-in-water type dispersion (direct system).
• direct system and reverse system will be mainly guided by the nature of the active substance that one wishes to encapsulate.
• liposoluble functionalized complexing agents it is advantageously preferred to carry out a dispersion in a direct system.
• water-soluble functionalized complexing agents the dispersion in the reverse system will be favorable.
• the use of one or the other of the systems may vary depending on the intrinsic nature of the complexing agents to be encapsulated.
• the solvent for the lipophilic phase is generally chosen from the usual organic solvents, such as toluene, cyclohexane, carbon tetrachloride, chloroform, etc. This is why, in the following description, this lipophilic phase will be referred to as the organic phase.
• a particularly suitable solution consists in carrying out the interfacial polycondensation reaction using an organic solvent having the solvation properties required for such a reaction, and which can be easily eliminated at the end of the reaction.
• a very suitable type of solvent is a gaseous solvent which can be brought into the liquid and / or supercritical state during the interfacial polycondensation reaction. After the reaction and return to normal temperature and pressure conditions, the said solvent is thus eliminated in the form of a gas.
• the solvents suitable for the interfacial polycondensation reaction according to the present invention further comprise all the gaseous compounds having the solvating properties required for such a reaction, inert with respect to the interfacial polycondensation reaction proper but also complexing agents, and which are in liquid or supercritical form under specific temperature and / or pressure conditions.
• Such gaseous compounds are for example air, oxygen, nitrogen, nitrous oxide, carbon dioxide, rare gases, halogenated or non-halogenated hydrocarbons, for example propane, butane , fluorocarbon compounds and others. As indicated above, these compounds are gaseous under normal conditions of temperature and pressure. Mixtures in all proportions of these compounds can also be used.
• a particularly preferred gaseous compound is carbon dioxide.
• a very particular organic solvent for ductuct, in fact, at availability and low cost, when it is desirable to avoid any trace of residual solvent in the capsules is carbon dioxide in the liquid state and / or supercritical. The process for the preparation of these capsules free of organic solvent is described in detail in patent application not yet published n ° FR 02 03939.
• the size of the capsules obtained by interfacial polycondensation in a dispersed medium is directly related to the size of the droplets present in the dispersion.
• the size of the latter is itself influenced by numerous parameters, the main ones being the speed with which the reaction medium is stirred and dispersed and the duration of the dispersion, the nature and concentration of the surfactant used, the nature, the viscosity and the volume ratio of each of the dispersing and dispersed phases, and finally, the temperature at which the dispersion and the polycondensation reaction are carried out.
• the present invention consists in providing capsules of sizes between a few nanometers and a few millimeters.
• the composite complexing capsules are preferably microcapsules or minicapsules, that is to say capsules having a diameter between approximately 1 ⁇ m and approximately 500 ⁇ m.
• w ⁇ teieicn ⁇ e e ⁇ ouie, ⁇ es capsules have an average diameter between about 100 microns and about 300 microns.
• the membrane of the capsule is generally obtained by polymerization of at least two monomers which are immiscible with one another. Indeed, at least one monomer must be soluble / miscible in the aqueous phase, and at least one other monomer soluble / miscible in the organic phase.
• monomers are well known to those skilled in the art and lead, for example, to the formation of a membrane of polyamide, polyester, polyurea, polyurethane, poly (ether-urethane) and poly (ether-urethane-urea) or one of their copolymers , to name only the best known of them.
• the term "monomer”, used here in this context, includes not only the monomers in the literal sense, but also the oligomers, telomeres and the like, having characteristics similar to those of the monomers described. above and leading to polymers constituting the membranes of the capsules suitable for the present invention. It can also be envisaged to use mixtures of monomers, oligomers, telomeres and the like, or else to replace or add a monomer, oligomer, telomer or the like, during the interfacial polycondensation reaction.
• the capsules whose membrane is a polyamide, polyester, polyurea, polyurethane, poly (ether-urethane) and poly (ether-urethane-urea) polymer or one of their copolymers are preferred. These polymers are chosen for their porosity to the various chemical entities which it is desired to complex, decomplex and / or separate. Polyamide membrane capsules have been found to be particularly satisfactory for the uses intended in the context of the present invention.
• polyamide, polyester, polyuree, polyurethane, poly (ether-urethane) and poly (ether-urethane-urea) polymers or one of their copolymers also have the advantage, at least ⁇ uui ocuaina u enue them, u eu non-toxic to the living human, animal or plant environment, that is to say to be biocompatible.
• Such capsules are particularly suitable for uses in the medical, biomedical, veterinary, cosmetic and phytosanitary fields.
• the composite capsules according to the present invention therefore have a more or less porous membrane with the various chemical entities which it is desired to complex, decomplex and / or even separate.
• the complexing, decomplexing and / or separating nature of the capsules is obtained thanks to the core of the capsule which comprises at least one complexing, decomplexing and / or separation agent.
• the agents capable or capable of complexing, decomplexing and / or separating chemical entities are chosen from the compounds known in the field for their capacity to fix and / or release metals, alkali or alkaline-earth metals and their isotopes , and the compounds, mineral or organic, these chemical entities being able to be in neutral, anionic or cationic form.
• 1- coronands which are monocyclic compounds comprising at least one, advantageously at least 3, preferably at least 4, atoms, identical or different chosen from oxygen, nitrogen, sulfur and phosphorus, one or more , or even all of these atoms can be replaced by divalent heterocyclic radicals;
• 2- cryptands, macrobicyclic compounds having two nitrogen atoms bridged by three links comprising at least one, advantageously at least 2, preferably at least 3, identical or different atoms chosen from oxygen, nitrogen, sulfur and phosphorus, one or more or even all of these atoms which can be replaced by divalent heterocyclic radicals;
• the pondands which are generally acyclic polyethers, are essentially characterized by the fact that they contain groups donor terminals, for example of the quinoiei ⁇ e, metnoxypnenoi or nitrophenol type.
• crown ethers a representative of which is coronand 18-C-6, also called crown ether 18-C-6, the structure of which is presented below. below:
• a representative of the class of cryptands is the cryptand 222B of structure:
• CPOD pondand an example of a neutral complexing ligand of the class of pondands is the CPOD pondand, the structure of which is as follows:
• a solution consists in grafting on complexing and / or decomplexing agents, such as those defined above, at least one polymerizable monomer. Once this or these monomer (s) has polymerized, the core of the capsule thus consists of a polymer chain grafted by a large number of complexing sites.
• Such polymer chains grafted with complexing groups are for example the poly (vinyl-ether-crown) disclosed in patent application JP-A-62-284 348.
• the length of the complexing polymer chains should advantageously be long enough to to avoid migration of these chains through a memorandum towards the outside of the capsule.
• any type of polymerizable monomer and functionalizing at least one complexing site chosen from the complexing molecules defined above may be suitable.
• Such monomers can be the subject of homopolymerization or copolymerization reactions, the co-monomer in the latter case possibly also comprising one or more complexing sites.
• the solution relating to the length of the complexing polymer chains recommended above can be supplemented or substituted by a more or less strong crosslinking of said chains, in order to form a network.
• crosslinking can be easily obtained according to conventional techniques known per se, for example by adding, during the polymerization, one or more crosslinking agents.
• Another crosslinking method can also consist in polymerizing complexing agents functionalized with two or more monomers. It is of course possible to combine these crosslinking techniques.
• the complexing polymer thus obtained also has an ue reuuuiauu ⁇ ⁇ ius or less, for example conferring greater rigidity on the core of the capsule and eliminating the risk of migration of the complexing polymer chains towards the outside of the capsules.
• the complexing polymers obtained can be in various forms.
• Preferred in the present invention are chemically crosslinked complexing polymers. This structure makes it possible to preserve the complexing / decomplexing power of the ligands and their selectivity.
• the membrane then has the mechanical strength characteristics in accordance with those required for the uses for which the composite capsules are intended.
• the polymerizable monomer (or oligomer, or telomer or other) which functionalizes the complexing molecules is chosen from the polymerizable monomers known to those skilled in the art. This monomer will preferably be chosen from those leading to homopolymerization reactions, this however not excluding the use of different monomers resulting in copolymers.
• Preferred polymerizable monomers are in particular those in which the polymerization reaction can be initiated, by radical route (chemical and / or photochemical and / or thermal), for example, the monomers comprising at least one unsaturation, preferably vinyl.
• radical route chemical and / or photochemical and / or thermal
• the monomers comprising at least one unsaturation, preferably vinyl.
• preference will be given to monomers having a vinyl function homopolymerizable by the radical route.
• the polymerizable monomers which can be used in the context of the present invention are the monomers originating from ethylenic hydrocarbons and their derivatives, in particular those chosen without limitation from ethylene, propene, chloride of vinyl, styrene, acrylonitrile, methyl methacrylate, acrylic acid, butadiene, isoprene and chloroprene.
• Complexing agents such as ue ⁇ e ⁇ reueuemme ⁇ i are grafted with one or more of these monomers.
• more than one, for example two, monomers are grafted onto a complexing agent.
• the complexing agent functionalized with at least one polymerizable monomer is soluble in the dispersed phase.
• the complexing agent functionalized with at least one polymerizable monomer when the synthesis of the capsule is carried out in a direct system, the complexing agent functionalized with at least one polymerizable monomer must have a coefficient of solubility in the lipophilic phase of the dispersion much higher than that which it has in the lipophobic phase.
• the complexing agent functionalized with at least one polymerizable monomer must have a coefficient of solubility in the lipophobic phase of the dispersion much higher than that which it has in the lipophilic phase.
• the complexing agents functionalized with at least one polymerizable monomer do not have the required miscibility in one or the other phase, it may be advantageous to add a hydrophilic or lipophilic component to it.
• This addition can for example be carried out by a chemical modification of the polymerizable monomer or monomers grafted on the complexing agent or also by a modification of the complexing agent itself.
• a monomer comprising both at least one vinyl double bond which can be polymerized by the radical route, and at least one hydrophilic group is for example the acryloyloxymethyl species, comprising both a vinyl double bond which can be polymerized by the radical, and a hydrophilic oxycarbonyl group.
• the complexing agent is chosen from the family of coronands functionalized with at least one polymerizable monomer, for example crown ether 18-C-6, substituted by one or more acryloyloxymethyl radicals of formula (I ): in which n represents an integer between 1 and 12, (limits included), preferably between 1 and 6, advantageously n represents 1, 2 or 3, better still, n represents 1 or 2.
• a particularly preferred complexing agent is acryloyloxymethyl-18-crown-6 (Compound A), described for example in patent application JP-A-62-284 348, that is to say the compound of formula (I) above where n represents 1:
• the compound (A) can be easily prepared from hydroxymethyl-18-crown-6 (available from Aldrich), on which the acryloyl chloride is reacted.
• Compound (A) defined above is homopolymerizable, for example by the radical route, and advantageously crosslinked using a crosslinking to provide a chemically recovered polymer.
• the crosslinking agent can be of any type known in the field of polymerization. The purpose of this is to bridge the complexing polymer chains together, that is to say to create a more or less dense network of polymer chains comprising complexing sites, linked together.
• the crosslinking agent is advantageously chosen from compounds comprising at least two vinyl functions, also allowing crosslinking by the radical route.
• the crosslinking agent can be N, N'-methylenebisacrylamide (MEBA).
• the functionalized complexing agents can be polymerized then the polymer chains optionally crosslinked before being encapsulated, or alternatively, and depending on the type of process used for the preparation of the capsules, during the synthesis of the capsules themselves, or still after the formation of said capsules.
• the synthesis of composite complexing capsules according to the present invention will be carried out by interfacial polycondensation in a dispersed medium, the complexing polymer forming the core of the capsule being obtained by radical polymerization of monomers in situ within the capsule once formed or during its formation.
• the present invention also consists in providing a process for the preparation of complexing composite capsules, characterized in that it comprises the following stages: - preparing with stirring a stabilized dispersion of a Pi phase comprising a solution, in at at least one solvent S, at least one monomer Mi and at least one monomer Me grafted on at least one complexing agent, optionally in the presence of a crosslinking agent, in a phase P 2 , comprising at least one solvent S 2 substantially immisciDie ⁇ ans ri and optionally a surfactant compatible with Si and S 2 ;
• the process for preparing complexing composite capsules characterized in that it comprises the following steps:
• the choice between direct system and reverse system will be mainly guided by the nature of the complexing agent that one wishes to encapsulate.
• it will advantageously be preferred to carry out a dispersion in a direct system.
• the dispersion in the reverse system will be favorable.
• the use of one or the other of the systems may vary depending on the intrinsic nature of the complexing agents to be encapsulated.
• the reverse system is the preferred interfacial polycondensation method according to the invention.
• the phase Pi is the aqueous phase dispersed in the organic phase P 2 .
• the monomer Mi as well as the monomer Me grafted on at least one complexing agent and optionally the crosslinking agent will be miscible with the lipophobic solvent Si, which will advantageously be water.
• Said reverse system thus allows the preparation of complexing composite capsules whose core is a polymer, possibly chemically crosslinked.
• the membranes of the capsules will thus be formed by polycondensation of at least two monomers Mi and M, one of which is soluble in the dispersing phase and another soluble in the dispersed phase.
• a solution comprising a monomer Mi dissolved in a solvent Si as well as the monomer Me grafted on the complexing agent and optionally the crosslinking agent is dispersed by stirring in a solution comprising a solvent S 2 .
• the monomer M 2 , soluble in S 2 , of the dispersing phase is added.
• the condensation reaction between Mi and M 2 possibly catalyzed, takes place at the interface of the dispersing phase and the dispersed phase.
• a solution comprising a monomer Mi dissolved in a solvent Si as well as the monomer (s) Me grafted (s) on the complexing agent, and optionally the crosslinking agent is dispersed by stirring in a solution comprising a solvent S 2 and the monomer M 2 .
• the condensation reactions between Mi and M 2 , optionally catalyzed, and of radical polymerization of the monomer e are carried out simultaneously.
• the volume ratio between the Pi phase and the P 2 phase, that is to say between the dispersed phase and the dispersing phase is generally between 20/1 and 1/20, preferably between 10/1 and 1/10.
• the dispersion of the Pi phase in the P 2 phase is stable, that is to say that the reaction medium does not undergo demixing, separation, decantation, etc.
• a surfactant which can be of any type, ionic or nonionic, and whose characteristic is to be spontaneously adsorbed at the interface of the two liquids.
• the dispersion stabilizing surfactant prevents the agglomeration of dispersed droplets therebetween, which will become the capsules, once the membrane growth phase has ended.
• the surfactants will advantageously be chosen from those which do not cause interaction between the different monomers present in the dispersion. Mixtures of surfactants can also be used.
• a very particularly preferred example of a surfactant suitable for interfacial polycondensation in a dispersed medium according to the invention is HYPERMER® B261, sold by ICI.
• the interfacial polycondensation reaction is most often carried out under normal conditions of temperature and pressure. It may however be advantageous in certain cases to heat or cool the reaction medium, according to the specific conditions required for the polycondensation or the polymerization of the complexing monomer. These conditions are known or easily accessible by a person skilled in the art.
• the composite complexing capsules according to the present invention are formed from a membrane permeable to various chemical entities.
• a membrane here consists of a polymer obtained by polycondensation of at least two monomers Mi and M 2 .
• the monomers Mi and M 2 must be chosen so that they can react with one another to form a polycondensate and be soluble, one in the aqueous phase, the other in the organic phase.
• the monomers Mi and M 2 are at least bi-functional monomers, that is to say that they each comprise at least two reactive functions, possibly different, preferably identical, per molecule.
• This bi-functionality ensures the formation of high molecular weight polymers, particularly suitable for the formation of capsules in the interfacial system of the invention.
• mono-functional monomers can indeed reduce or even stop the growth of the polymer chains, before they have reached the length suitable for the formation of capsules.
• pol - functionalized monomers will behave like crosslinking agents, thus causing a very rapid increase in the molecular mass of the polymer formed, the formation of a three-dimensional network and very often the precipitation of the macromolecule.
• Such monofunctional and polyfunctional monomers can however be used for the synthesis of the capsules of the present invention.
• polyfunctional monomers can advantageously be used as crosslinking agent, in order to accelerate and / or promote the formation of the polymer membrane.
• the copolymer obtained from the monomers Mi and M 2 , and which forms the membrane of said capsules either not toxic, biocompatible and / or bioassimilable for the uses for which they are intended. This same biocompatibility and / or bioassimilation must also be observed for the degradation products of the polymer, degradation which can for example intervene by chemical or biochemical degradation (metabolization).
• the "organic” monomers are for example chosen from diisocyanates, for example methylene diphenylisocyanate (MDI), 4,4'-dicyclohexylmethanediisocyanate (H ⁇ 2 MDI), toluenediisocyanate (TDI), poly (1, 4-butanedioltoluènediisocyanate) (PBTDI) and polyfunctional aliphatic polyisocyanates, for example DESMODUR® N100 sold by the company Bayer.
• the "organic” monomers can also be acid dichlorides, such as terephthaloyl dichloride or sebacoyl dichloride.
• aqueous monomers that is to say water-soluble, or even soluble in the aqueous phase
• aqueous monomers are for example chosen from alkane diols, such as 1,4-butanediol or 1,5-pentanediol, poly (ethylene glycol oxides) (POEG) of various molecular weights, among alkane polyols, for example alkane triols such as trimethylolpropane, and among the di- or polyamines, for example 1, 6-hexamethylene diamine, 1, 2-ethylenediamine and tri- (2-aminoethyl) amine.
• alkane diols such as 1,4-butanediol or 1,5-pentanediol
• POEG poly (ethylene glycol oxides)
• alkane polyols for example alkane triols such as trimethylolpropane
• di- or polyamines for example 1, 6-hexamethylene diamine, 1, 2-ethylenedi
• polycondensation between one or more "organic” monomers and one or more "aqueous” monomers.
• the polycondensates thus obtained will be random or non-random copolymers of two, three, four or more monomers.
• an "aqueous" monomer of the diamine type and an “organic” monomer of the acid dichloride type will advantageously be used, so as to form capsules whose membrane will consist essentially of polyamide.
• Polycondensation reactions between the monomers Mi and M 2 defined above can optionally be accelerated under the action of one or more catalysts.
• the nature of the catalyst to be used depends on the nature of the monomers which must react with one another and are perfectly known to those skilled in the art, specialist in the synthesis of macromolecules.
• co-solvents whether in the aqueous phase or in the organic phase is not excluded.
• Such co-solvents can be effect necessary to improve the solubility of the monomers in water or in the organic solvent.
• the choice of such co-solvents must therefore be made according to the nature of the monomers involved in the interfacial polycondensation reaction, the nature of the functionalized complexing agent (s), and any surfactants and catalysts present in the reaction medium.
• the composite capsule thus obtained consists of a polymer membrane resulting from the polycondensation of the monomers defined above, that is to say a polyamide, polyester, polyurethane, polyurea, poly (ether-urethane) or poly ( ether-urethane-urea) or a copolymer of these polymers, and of a core filled with one or more polymerizable monomers Me, advantageously homopolymerizable, preferably by radical route, grafted on one or more complexing agents, grafted monomers which will have have been previously introduced into the dispersed phase, optionally in the presence of a crosslinking agent.
• the monomer grafted on the complexing agent and present in the heart of the capsule is preferably a polymerizable monomer by the radical route. This type of polymerization is preferred over polycondensation reactions so as not to interfere with the polymerization which takes place for the formation of the membrane.
• the polymerization of this grafted monomer may be carried out, during or after the formation of the membrane of the capsules, in situ, according to any technique known per se to those skilled in the art.
• the radical polymerization of vinyl unsaturated monomers can be initiated by slight heating of the reaction medium, allowing the activation of a radical polymerization initiator, such as for example 4,4'-azobis- ( 4- cyanovaleric) (ACVA).
• a radical polymerization initiator such as for example 4,4'-azobis- ( 4- cyanovaleric) (ACVA).
• the amount of complexing agent, in the form of an optionally chemically crosslinked polymer, present in the heart of the capsule mainly depends the size of said capsules and therefore the size of the dispersed droplets.
• the amount of complexing agent in the dispersed phase will advantageously be between 1% and 99% by weight for obtaining capsules of size between 1 ⁇ m and 500 ⁇ m of average diameter.
• the capsules After the polycondensation reaction and the polymerization of the encapsulated monomer (s), the capsules are washed. During this washing phase, the use of a surfactant may prove necessary in order to prevent agglomeration of the capsules formed.
• the core of the capsule contains a polymer, homopolymer or copolymer, advantageously chemically crosslinked, functionalized with complexing and / or decomplexing agents, which polymer thus preventing said agents from migrating towards the outside of the capsule.
• the composite complexing capsules of the invention are for example capable of being able to complex and / or specifically decomplex chemical entities present in a given medium.
• a first use can thus be found in pollution control, for example of liquids, soils, etc. by selective complexation of the polluting agent.
• This polluting agent will thus be retained inside the capsules, which will then suffice to recover by any means known per se, (for example filtration, sieving).
• the applications are in this case very numerous and relate particularly to the depollution of soils, clothing, liquids, etc., containing radioactive or simply toxic compounds or elements.
• the encapsulated complexing agents generally have different complexation kinetics depending on the nature of the chemical entities.
• the capsules according to the invention can therefore also be used as means of separation of several different chemical entities, for example metal cations.
• the capsules will in this case be very advantageously used as filling elements for elution chromatography columns.
• the capsules also present an alternative to ion exchange resins or liquid-liquid extractions.
• the extraction makes it possible to separate different ions but also their isotopes. So we can consider the use of these capsules for isotopic enrichment.
• the crown ethers and their analogs are capable of complexing different cations such as the alkalis and the alkaline earths, this thanks to their hydrophilic cavity.
• 18-crown-6 ether is capable of complexing a cation such as strontium.
• the composite complexing capsules according to the present invention when they are prepared in the absence of toxic organic solvent, or with a gaseous organic solvent under normal conditions of temperature and pressure, used in the liquid or supercritical state , such as carbon dioxide for example, and consist of a biocompatible polymer membrane, have the advantage of being able to be used in the fields of human or animal therapy, in cosmetics or even in the food or phytosanitary fields.
• the capsules may thus be used as a blood depollution agent.
• the composite complexing capsules according to the invention can be used as such or else enter into the manufacture of complexing and / or decomplexing and / or separation products, for industrial or domestic uses or even in the manufacture of pharmaceutical products.
• veterinary, cosmetics such as tablets, capsules, powders, patches, gels, creams, ointments, but also in the manufacture of products for medical imaging (for example contrast agent) or of textile products, for example in the field medical and / or paramedical and the field of civil protection.
• medical imaging for example contrast agent
• textile products for example in the field medical and / or paramedical and the field of civil protection.
• Solution 3 are dissolved in 10 mL of deionized water: o 1 g (8.61.10 “3 moles) of hexamethylenediamine, o 1, 444 g (1.72.10 “ 2 moles) of sodium hydrogen carbonate, o 1 g (2.87.10 “3 moles) of monomer A obtained as indicated above, and o 0.044 g (2.85.10 " 4 moles) of N, N'-methylenebisacrylamide (MEBA).
• Solution 4 are dissolved in 5 mL of deionized water: o 0.0403 g (1.44.10 -4 moles) of 4,4'-azobis- (4-cyanovaleric) acid (ACVA), and o 0, 0241 g (2.87.10 "4 moles) sodium hydrogen carbonate.
• the prepared solutions are first degassed for 1 hour under a stream of argon.
• the reactor is also conditioned under an argon atmosphere.
• 150 ml of organic phase (solution 1) are introduced into the reactor.
• the stirring is fixed at 800 rpm "1.
• the two aqueous phases (solutions 3 and 4) are then mixed separately in a beaker, then added to the reaction medium.
• the stirring system is stabilized at 800 rpm "1 for 2 minutes.
• the temperature of the reaction mixture is increased to 60 ° C using a thermostatically controlled bath for 3 hours. Heating then initiates the radical polymerization reaction in situ. Finally, the medium is heated at 70 ° C for 1 hour, to complete the radical polymerization. At the end of the reaction, an amount (150 ml) of dispersing phase is added to the mixture, and the polycondensation reaction is considered to be stopped. In fact, the reaction is not really stopped, but considerably slowed down.
• the minicapsules obtained are then filtered on paper, then washed successively with aqueous solutions of TWEEN® 20 of decreasing concentrations (3 x 100 mL at 5 gL “1 , 3 x 100 mL at 2.5 gL “ 1 and 3 x 100mL at 1 gL “ 1 ), then with deionized water (2 x 120 mL).
• the topographic characteristics of the complexing capsules thus synthesized are determined by observation with an optical microscope as well as with a scanning electron microscope.
• the complexing capsules have sizes between 100 ⁇ m and 300 ⁇ m in diameter.
• Figure 1 presents the result of this conductimetry study (expressed as a strontium concentration as a function of time) carried out with reference capsules (•) and complexing capsules (A):
• the strontium ion concentration is 140 mmol / L (140.1 mmol / L for the capsules reference and 139.8 mmol / L for complexing capsules) with a measurement error of 0.3 mmol / L (accuracy of the conductivity meter 0.2%);
• the concentration of strontium ions in the solution drops (125.3 mmol / L for the reference capsules and 123.5 mmol / L for the complexing capsules)
• the variation in concentration of strontium ions in the solution containing the complexing capsules of the invention (16.3 mmol / L) is greater than that observed for the solution containing the reference capsules (14.8 mmol / L). This is due to the fact that the complexing capsules have effectively complexed part of the strontium ions which are then no longer detectable by the electrode, hence a lower residual strontium concentration.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Analytical Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Manufacturing Of Micro-Capsules (AREA)
• Medicinal Preparation (AREA)

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  • 2002-04-23 FR FR0205096A patent/FR2838655B1/fr not_active Expired - Fee Related
• 2003
  • 2003-04-17 WO PCT/FR2003/001246 patent/WO2003090921A1/fr active IP Right Grant
  • 2003-04-17 EP EP03747146A patent/EP1497022B1/de not_active Expired - Lifetime
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  • 2003-04-17 AU AU2003251026A patent/AU2003251026A1/en not_active Abandoned
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